Preoperative nutritional support to tackle morbidity in multivisceral resection for retroperitoneal sarcoma. Early outcomes from a novel nutritional prehabilitation program in a prospective cohort

Objective: Evaluate the feasibility and outcomes of the implementation of a routinely prehabilitation nutritional program (PNP) in retroperitoneal sarcoma (RPS) patients. Summary background data: Rate of preoperative malnutrition is scarcely evaluated in RPS patients and the efficacy of a PNP in detecting and reverting malnutrition has not been studied. Methods: Prospective study in a high-volume reference center for RPS; adult patients with primary or persistent RPS deemed surgically resectable were enrolled in a PNP. Results: 119 patients underwent surgery for RPS at Fondazione IRCCS Istituto Nazionale dei Tumori in Milan, 73 (61.3 %) were enrolled in the PNP while the remaining served as control cohort. 43.8 % (32/73), 28.8 % (21/ 73), and 27.4 % (20/73) were classified as non-malnourished, moderately malnourished, and severely malnourished at diagnosis, respectively. Preoperative nutritional support was provided to 35 out of 73 patients (47.9 %). Among untreated patients 20 of 38 (52.6 %) experienced a preoperative worsening of their nutritional status, whereas among those in the prehabilitation program 16 of 35 (45.7 %) showed improvement. Surgical complications did not significantly differ between malnourished and non-malnourished patients, potentially due to increased use of diverting stomas in malnourished patients to prevent infectious complications. Reversal of initial malnutrition correlated with better postoperative outcomes, as evidenced by lower rates of severe complications (OR: 0.18, 95%CI 0.04-0.75, p = 0.02) and a lower Comprehensive Complication Index (OR: -0.28, 95%CI -0.51 to -0.06, p = 0.02) in multivariate analysis. Conclusions: The implementation of a prehabilitation nutritional program brought relevant benefits in terms of postoperative morbidity.